1. Field of the Invention
The invention relates to an image display device comprising a plurality of gate buses, a plurality of source buses, transistors each of which for supplying a pixel electrode with a voltage from said source bus, a common electrode, and a corrected voltage supplying means for supplying said common electrode with a common electrode voltage which has been corrected by an amount of correction.
2. Description of Related Art
Prior to shipment of a liquid crystal display device, a voltage level on a common electrode is adjusted. For the purpose of the adjustment, the liquid crystal display device is provided with, for example, a variable resistor connected to the common and an adjustment knob for adjusting a resistance value of the variable resistor. The adjustment knob is manipulated by a person or machine, so that the voltage level on the common electrode is adjusted in such a way that a flicker level become minimized.
In the manner described above, since the variable resistor is required, there is a problem that a component cost of the resistor is required. Further, if the resistance value of the variable resistor is adjusted by a person, there is a problem that it is difficult to adjust the voltage level on the common electrode to an optimum level since positions of the adjusted adjustment knob vary among persons who adjust the adjustment knob, on the other hand, if the resistance value of the variable resistor is adjusted by a machine, there is a problem that an equipment cost is required since an equipment provided with photo sensors for receiving light emitted from a display panel and an adjustment system for adjusting the adjustment knob is required. Further, if the resistance value of the variable resistor is adjusted with the adjustment knob, the person or machine touches the adjustment knob and then manipulates the adjustment knob, so that there is a fear of occurring a slightly variation of the position of the adjustment knob at the instant when the person or machine releases the adjustment knob. Therefore, even if the adjustment knob is on the optimum position immediately before the person or machine releases the adjustment knob, there is a fear of occurring a slightly deviation of the position of the adjustment knob from the optimum position immediately after the person or machine releases the adjustment knob, so that it is difficult to adjust the voltage level on the common electrode to the optimum level.
It is an object of the invention is to provide an image display device in which the component cost and the equipment cost are reduced and a voltage level of a common electrode is easily adjustable to an optimum level.